In 3D High Efficiency Video Coding (hereinafter, 3D-HEVC), inter mode depth encoding units can be divided in manners such as 2N×2N, 2N×N, 2N×nU, 2N×nD, N×2N, nL×2N, nR×2N and N×N and so on. FIG. 9 is a schematic of dividing manners of the inter mode depth encoding units in 3D-HEVC. Wherein, N is one of 4, 8, 16 and 32; n=N/2, U means up, D means down; L means left, and R means right. When a residual of a depth encoding unit is encoded, operations such as transformation, quantization and the like are needed to be conducted to residual signals as to all dividing manners; and operations such as corresponding inverse quantization, inverse transformation and the like are needed to be conducted in decoding.
Therefore it is urgent for those skilled in the art to solve problem of low efficiency caused by complicated processing in depth picture inter encoding and decoding.